The 66 books of the Bible comprise the unique, authoritative word of God as taught in Scripture and affirmed throughout church history.


Christians believe that the sixty-six books of the Bible constitute the Word of God. The Bible may also be referred to as “the canon,” meaning that it is the standard by which all other things in the Christian life are judged. However, can we say with confidence that the canon is now closed? In order to answer this question, one must consider what the Scriptures say about themselves and what the church has affirmed historically. Finally, it is also important to consider the sufficiency of Scripture for Christian living. Each of these tenets helps lay a confidence for the Christian that the canon is now closed. This now inspires the Christian to value God’s Word more deeply and press greater into the precious gift of his word.


When Christians speak of “the canon,” we are referring to the ancient, divinely-inspired writings which make up the Bible. Now that Jesus is at the right hand of God (Rom. 8:34) and we live in anticipation of his coming again (Rev. 22:12-13), should we anticipate new revelation from God to add to the Bible? Are books of Scripture still to be written as we live in the in-between time of the ascension and the second coming? That is, is the canon of Scripture closed? Roman Catholicism elevates certain aspects of its Tradition to the level of Scripture.1 Mormonism does the same with the works of Joseph Smith.2 Is it right to accept additions to the biblical books as equally authoritative? As we delve into this important question, we will consider the witness of the Scriptures themselves, the witness of both redemptive and church history, and the sufficiency of God’s written Word.

The Canon Defined

The English word “canon” comes from the Greek word kanon, a straight rod used as a rule – like our measuring stick. The idea is that Scripture is the standard by which the truths about God are refined. The third question of the Westminster Larger Catechism corroborates this language when it refers to the Bible as “the only rule of faith and obedience.”3 Likewise, we can think of the historic Protestant doctrine of “Scripture interpreting Scripture” (that is, the clearer portions of Scripture interpret the less clear). These principles remind us of the complete trustworthiness of Scripture and show us that despite our ever-changing circumstances, Scripture remains a firm and settled foundation.

The Witness of Scripture

We may begin with a consideration of how the Bible refers to itself. An excellent summation verse of both the trajectory and contents of Scripture can be found at the beginning of the letter to the Hebrews: “Long ago, at many times and in many ways, God spoke to our fathers by the prophets, but in these last days he has spoken to us by his Son, whom he appointed the heir of all things, through whom he also created the world” (Heb. 1:1-2). The thirty-nine books comprising the Old Testament record God’s words to his people spoken through individuals such as Moses, Samuel, David, and Isaiah. We read that the prophets of the Old Testament “spoke from God, as they were carried along by the Holy Spirit” (2Pet. 1:21). We can think, for example, of Moses on Mount Sinai who receives the law from God soon after the exodus from Egypt (Exod. 31:18). Moses then gives Israel God’s law and exhorts them to keep God’s commandments, stating that “the secret things belong to the LORD our God, but the things that are revealed belong to us and to our children forever, that we may do all the words of this law” (Deut. 29:29). We can think of the judges of Israel, whom God raises up to rescue “[Israel]” out of the hand of those who plundered them (Jdg. 2:16). The Old Testament is a record of God’s doings amongst his people and the way he salvifically works through prophets, priests and kings that prefigure the coming of the ultimate Prophet, Priest and King.

When Jesus came to earth, “the Word became flesh and dwelt among us” (John 1:14a). Jesus, the creator and Lord of the universe, revealed himself fully to his creation by humbling himself and becoming a man (Eph. 2:16; Phil. 2:7-8). No more would there be a need for another mediator or additional revelation after God revealed himself so completely. John 12:32 echoes the ancient promise of world-wide blessing, when Jesus declares, “And I, when I am lifted up from the earth, will draw all people to myself.”  The salvation which the Old Testament prophets spoke of has finally come.

Now the Scriptures speak of waiting in anticipation for Christ’s return to make things new as seen most fully in the book of Revelation. Revelation ends with a stern warning as the book concludes: “I warn everyone who hears the words of the prophecy of this book: if anyone adds to them, God will add to him the plagues described in this book, and if anyone takes away from the words of the book of this prophecy, God will take away his share in the tree of life and in the holy city, which are described in this book” (Rev. 22:18-19). Clearly, the Christian is not to add anything to the prophecies of Revelation. Rather, instead, we are to “keep” what is written in God’s Word and anticipate Christ’s return “for the time is near” (Rev. 1:3).

Moreover, it is important to note that it is the Lord Jesus Christ himself who directs us to understand the canon as closed. He clearly recognized the inspiration and authority of the Old Testament Scriptures (e.g., Luke 24:44), and he did the same for the New Testament Scriptures, only ahead of time. In John 14-16 he promised his apostles that he would send the Spirit for just this purpose (John 14:16-18, 25-26; 15:26-27; 16:7, 12-15; cf. 17:20). His promise is not just general, that these men would produce the Scriptures, but that “all truth” would be given them (16:13). This complete body of truth “once for all revealed” from Jesus to the apostles, became, in turn, the “deposit” entrusted to the church (1Tim.6:20; cf. Jude 3). In brief, the Lord Jesus himself affirmed the Old Testament canon after the fact, and he affirmed the New Testament canon in appointing his apostles for just that task.

The Witness of History

The closing of the canon is not only witnessed to by Scripture itself but also by the testimony of the early church. For example, the Didache, an ancient document used by the early church, commands the Christian to “not forsake the commandments of the Lord, but you shall keep the things you received, neither adding nor taking away.”4 Likewise, Josephus, the Jewish historian, wrote of the Jewish scriptures that “although such long ages have now gone by, no one has dared to add anything to them, to take away anything from them, or to change anything in them.’”5

It is also important to note that the first list of the canonical twenty-seven books of the New Testament came in 367 A.D. by the great early church father and defender of the faith, Athanasius.6 Robert Plummer notes that while this date may seem late to some concerning the final list of the New Testament, the books comprising the New Testament had already been circulating amongst Christians for at least two hundred years after they were written (45 AD – 100 AD).7 Therefore, Christians have been reading the same materials in their New Testaments since the very beginning.

Moreover, it is important to note that the early church did not “create” the canon or otherwise bestow canonical status on the New Testament books – it merely discovered and recognized the inspiration and therefore the canonical status of these books and accepted them as such.

A clear understanding of the finality of the canon in the early church was also important for identifying early heresies which contrasted with orthodoxy. For example, many Gnostic “Gospels” appeared in the second century that disputed the claim that there could be more than one gospel (therefore rejecting the four gospels) and were simultaneously rejected by those who held to orthodoxy.8 Gnosticism stressed a “secret knowledge” that one needed in order to obtain salvation and viewed God’s material creation is both evil and not real.9 Both ideas stand in complete contrast to the beauty and wonder of the incarnation of the Son of God where “the Word became flesh and dwelt among us” (John 1:14a). Jesus not only affirmed the fundamental goodness of creation by becoming flesh but on the cross, he demonstrated his perfect love for his creation. Therefore, writings that propagated truths that denied God’s goodness in entering into the physical and material world could not be considered canonical.

The Sufficiency of Scripture

The question of the closing of the canon is closely linked to the doctrine of the sufficiency of Scripture. In other words, do we truly believe that God’s Word is enough for us or should we be expecting more revelation from him? We do well to remember Paul’s words to Timothy in 2 Timothy 3:16-17 that “all Scripture is breathed out by God and profitable for teaching, for reproof, for correction and for training in righteousness, that the man of God may be complete, equipped for every good work.” God has certainly not silenced himself; he continues to convict and direct his children through his Holy Spirit and his Word.

Psalm 19 is a wonderful text from the Old Testament that spends several verses reflecting on both God’s creation and God’s law. In reflecting on this psalm, the late James Montgomery Boice saw David making a clear statement about the beauties and riches of God’s written word: “the revelation of God in nature is wonderful but limited. By contrast, the revelation of God in Scripture is perfect, trustworthy, right, radiant, pure, sure, precious sweet and rewarding.”10 In a world where many things are vying for our attention and where many people are telling us what to believe based on social or cultural norms, God’s Word remains a firm and solid foundation for us.

The Psalms also describe God’s Word as being equivalent to the very character of our God in that both him and his word do not change despite our ever-changing circumstances: “forever, O LORD, your word is firmly fixed in the heavens. Your faithfulness endures to all generations; you have established the earth, and it stands fast” (Psa. 119:89-90). New trends will come in and out of vogue, but God remains faithful to his people and to the promises that he has made in his word. Remember Paul’s summation of the promises made in God’s Word: “for all the promises of God find their Yes in him [Jesus]” (2Cor. 1:20).


In thinking about the canon of Scripture we must take into account what Scripture says about itself, what church history has said about the Scriptures, and also the sufficiency of the Scriptures themselves for communing with and learning about God. Each of these testifies that the canon of Scripture is now closed. Do not misinterpret this in thinking that God no longer leads his people or that our prayers fall on deaf ears! Rather, we now have the full revelation of God in Jesus Christ which Scripture testifies of. The first stanza of the classic hymn “How Firm a Foundation” sums this up well: “How firm a foundation, ye saints of the Lord, is laid for your faith in his excellent word! What more can he say than to you he hath said, to you who for refuge to Jesus have fled?”11


1Cf. Gregg Allison, Roman Catholic Theology and Practice: An Evangelical Assessment (Crossway, 2014), 78-95.
2Cf. Kevin DeYoung, “Mormonism 101”
3Westminster Larger Catechism, Q.3 in The Westminster Standards (Suwannee, GA: Great Commissions Publications, 2011), 35.
4Didache 4.13. Cited in Bruce, The Canon of Scripture, 23.
5Josephus, Against Apion, 1.42. Cited in Bruce, The Canon of Scripture, 23.
6Robert L. Plummer, 40 Questions about Interpreting the Bible, Benjamin L. Merkle series editor (Kregel Publications, 2010), 60.
7Ibid., 61.
8Justo L. Gonzalez, The Story of Christianity Volume 1: The Early Church to the Dawn of the Reformation Revised and Updated (HarperOne Publishers, 2010), 76.
9Ibid., 70.
10James Montgomery Boice, Standing on the Rock: Biblical Authority in a Secular Age (Baker Books, 1994), 135.
11“How firm a foundation, ye saints of the Lord” (accessed September 4, 2019).

Further Reading

This essay is part of the Concise Theology series. All views expressed in this essay are those of the author. This essay is freely available under Creative Commons License with Attribution-ShareAlike (CC BY-SA 3.0 US), allowing users to share it in other mediums/formats and adapt/translate the content as long as an attribution link, indication of changes, and the same Creative Commons License applies to that material. If you are interested in translating our content or are interested in joining our community of translators, please reach out to us.